BRIEF SUMMARY OF THE INVENTION
This invention relates to an automatic contour tracking method for a CAD (computer aided drawing system).
The contour tracking of drawing on a display has heretofore been carried out semiautomatically. In case of the contour tracking of the drawing on the display shown in FIG. 19, the tracking of the contour from a start point S to an extreme point a on an element line segment is possible, but the motion of the tracking stops at the extreme point a. When an operator at this time indicates an outside , an automatic tracking of the element of drawing to the next extreme point b takes place, and the operator indicates again which is chosen at this position.
As described in the foregoing, in the case of the semi-automatic tracking function, the operator's indication has to be made on which tracking ought to be made whenever the tracking is stopped at the extreme point, which results in the drawback of a poor manipulation property. An object of this invention is to eliminate the foregoing drawback.